Emergency department (ED) overcrowding was declared a ?crisis? by the Institute of Medicine 10 years ago, and EDs have become more crowded since. Patients treated in overcrowded EDs are at increased risk for subsequent cardiovascular disease (CVD) and psychiatric disorder, largely due to increases in patients? psychological stress during their acute care stay. While the association of ED stressors with patient CVD and psychological outcomes is established, little work has explored the impact of ED environmental factors on the nurses and doctors who spend years exposed to stressful and frequently overcrowded EDs?often after poor sleep due to shift-work. This study will test whether modifiable ED factors and/or short sleep increase ambulatory blood pressure (ABP) and psychological risk in ED clinicians Whereas 45% of the 1 million physicians in the U.S. report symptoms of burnout, an astonishing 70% of ED providers report burnout symptoms (i.e., emotional exhaustion, depersonalization, and reduced personal accomplishment). There is evidence that aspects of acute care work (crowding, acute and chronic stress, shift work) may contribute to burnout risk, which is related to worse patient care and more medical errors, and is also an independent risk factor for CVD. Burnout is associated with 37% increased risk for coronary heart disease (CHD) events, independent of age, body mass index, smoking, and lipid levels. Proposed physiological mechanisms for the association of burnout with CVD include autonomic dysregulation and increased blood pressure. Similarly, recent meta-analyses have shown short sleep (<6 hours) is associated with incident CHD risk (RR=1.26), likely through similar pathways. Circadian misalignment, another consequence of shift work common in ED providers, also increases CVD risk. We will test the influence of ED factors, sleep, and circadian misalignment on ABP (a primary marker of CVD risk) and burnout in an innovative study design, leveraging our expertise in ED research, behavioral cardiology, and sleep. We will prospectively follow a cohort of ED physicians and nurses for 3 years, testing the hypothesis that ED work factors (e.g. ED overcrowding, short sleep, and circadian misalignment due to shift work), increase burnout and contribute to increased ABP. We will continually capture ED data on patient volume, acuity, and staffing. Annually, participants will complete a 2-week burst, monitoring sleep duration, circadian misalignment, and work-related stress. During each burst, we will assess burnout, job strain, and 24-hour ABP. This design will allow us to: 1) evaluate the short-term contribution of ED crowding, circadian misalignment, and short sleep to acute changes in ABP and psychological risk 2) characterize the relationship of cumulative ED stress exposures and sleep impairment to 3-year progression of CVD and psychological risk.